C#.NET RSA 私钥签名 公钥验证签名 公钥验签
1.待签名字符串转为byte数组时，一般使用UTF8。
2.将私钥字符串（PKCS8或PKCS1格式）转为C#.NET的RSACryptoServiceProvider对象。
3.使用RSACryptoServiceProvider对象的SignData方法算出签名值，结果为byte数组。
4.签名值是byte数组，不便于传输，一般是转为BASE64字符串来传输。
5.RSACryptoServiceProvider对象+SHA256算法，对标JAVA的SHA256withRSA。
6.openssl生成的私钥默认是PKCS1的，示例中是转成了PKCS8格式，在解决方案的“公私钥”文件夹，用记事本打开，填入程序即可。
7.如果要和其它语言互通，需要协商好：待签名字符串转为byte数组的编码、签名值byte数组转字符串的编码、哈希算法（SHA1WithRSA 还是 SHA256WithRSA）。
私钥签名：
private void btnSign_Click(object sender, EventArgs e) { try { if (string.IsNullOrWhiteSpace(txtPrivateKey.Text) || string.IsNullOrWhiteSpace(txtToSignStr.Text)) { MessageBox.Show("私钥和字符串不能为空"); return; } //SHA256withRSA string fnstr = txtToSignStr.Text;//待签名字符串 //1。转换私钥字符串为RSACryptoServiceProvider对象 RSACryptoServiceProvider rsaP = RsaUtil.LoadPrivateKey(txtPrivateKey.Text, "PKCS8"); byte[] data = Encoding.UTF8.GetBytes(fnstr);//待签名字符串转成byte数组，UTF8 byte[] byteSign = rsaP.SignData(data, "SHA256");//对应JAVA的RSAwithSHA256 string sign = Convert.ToBase64String(byteSign);//签名byte数组转为BASE64字符串 txtSign.Text = sign; } catch (Exception ex) { MessageBox.Show(ex.Message); } }
公钥验证签名：
private void button1_Click(object sender, EventArgs e) { try { if (string.IsNullOrWhiteSpace(txtPubKey.Text) || string.IsNullOrWhiteSpace(txtToSignStr.Text) || string.IsNullOrWhiteSpace(txtSign.Text)) { MessageBox.Show("公钥，签名字符串，签名 不能为空"); return; } byte[] signature = Convert.FromBase64String(txtSign.Text);//签名值转为byte数组 //SHA256withRSA string fnstr = txtToSignStr.Text; //1。转换私钥字符串为RSACryptoServiceProvider对象 RSACryptoServiceProvider rsaP = RsaUtil.LoadPublicKey(txtPubKey.Text ); byte[] data = Encoding.UTF8.GetBytes(fnstr);//待签名字符串转成byte数组，UTF8 bool validSign = rsaP.VerifyData(data, "SHA256", signature);//对应JAVA的RSAwithSHA256 if(validSign) lblValidRst.Text = "验证签名通过："+DateTime.Now.ToString(); else lblValidRst.Text = "验证签名 不通过：" + DateTime.Now.ToString(); } catch (Exception ex) { MessageBox.Show(ex.Message); } }
工具类：
using Org.BouncyCastle.Crypto.Parameters; using Org.BouncyCastle.Security; using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Security.Cryptography; using System.Security.Cryptography.X509Certificates; using System.Text; using System.Threading.Tasks; namespace CommonUtils { public static class RsaUtil { #region 加载私钥 /// <summary> /// 转换私钥字符串为RSACryptoServiceProvider /// </summary> /// <param name="privateKeyStr">私钥字符串</param> /// <param name="keyFormat">PKCS8,PKCS1</param> /// <param name="signType">RSA 私钥长度1024 ,RSA2 私钥长度2048</param> /// <returns></returns> public static RSACryptoServiceProvider LoadPrivateKey(string privateKeyStr, string keyFormat) { string signType = "RSA"; if (privateKeyStr.Length > 1024) { signType = "RSA2"; } //PKCS8,PKCS1 if (keyFormat == "PKCS1") { return LoadPrivateKeyPKCS1(privateKeyStr, signType); } else { return LoadPrivateKeyPKCS8(privateKeyStr); } } /// <summary> /// PKCS1 格式私钥转 RSACryptoServiceProvider 对象 /// </summary> /// <param name="strKey">pcsk1 私钥的文本内容</param> /// <param name="signType">RSA 私钥长度1024 ,RSA2 私钥长度2048 </param> /// <returns></returns> public static RSACryptoServiceProvider LoadPrivateKeyPKCS1(string privateKeyPemPkcs1, string signType) { try { privateKeyPemPkcs1 = privateKeyPemPkcs1.Replace("-----BEGIN RSA PRIVATE KEY-----", "").Replace("-----END RSA PRIVATE KEY-----", "").Replace(" ", "").Replace(" ", "").Trim(); privateKeyPemPkcs1 = privateKeyPemPkcs1.Replace("-----BEGIN PRIVATE KEY-----", "").Replace("-----END PRIVATE KEY-----", "").Replace(" ", "").Replace(" ", "").Trim(); byte[] data = null; //读取带 data = Convert.FromBase64String(privateKeyPemPkcs1); RSACryptoServiceProvider rsa = DecodeRSAPrivateKey(data, signType); return rsa; } catch (Exception ex) { throw ex; } return null; } private static RSACryptoServiceProvider DecodeRSAPrivateKey(byte[] privkey, string signType) { byte[] MODULUS, E, D, P, Q, DP, DQ, IQ; // --------- Set up stream to decode the asn.1 encoded RSA private key ------ MemoryStream mem = new MemoryStream(privkey); BinaryReader binr = new BinaryReader(mem); //wrap Memory Stream with BinaryReader for easy reading byte bt = 0; ushort twobytes = 0; int elems = 0; try { twobytes = binr.ReadUInt16(); if (twobytes == 0x8130) //data read as little endian order (actual data order for Sequence is 30 81) binr.ReadByte(); //advance 1 byte else if (twobytes == 0x8230) binr.ReadInt16(); //advance 2 bytes else return null; twobytes = binr.ReadUInt16(); if (twobytes != 0x0102) //version number return null; bt = binr.ReadByte(); if (bt != 0x00) return null; //------ all private key components are Integer sequences ---- elems = GetIntegerSize(binr); MODULUS = binr.ReadBytes(elems); elems = GetIntegerSize(binr); E = binr.ReadBytes(elems); elems = GetIntegerSize(binr); D = binr.ReadBytes(elems); elems = GetIntegerSize(binr); P = binr.ReadBytes(elems); elems = GetIntegerSize(binr); Q = binr.ReadBytes(elems); elems = GetIntegerSize(binr); DP = binr.ReadBytes(elems); elems = GetIntegerSize(binr); DQ = binr.ReadBytes(elems); elems = GetIntegerSize(binr); IQ = binr.ReadBytes(elems); // ------- create RSACryptoServiceProvider instance and initialize with public key ----- CspParameters CspParameters = new CspParameters(); CspParameters.Flags = CspProviderFlags.UseMachineKeyStore; int bitLen = 1024; if ("RSA2".Equals(signType)) { bitLen = 2048; } RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(bitLen, CspParameters); //RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(); RSAParameters RSAparams = new RSAParameters(); RSAparams.Modulus = MODULUS; RSAparams.Exponent = E; RSAparams.D = D; RSAparams.P = P; RSAparams.Q = Q; RSAparams.DP = DP; RSAparams.DQ = DQ; RSAparams.InverseQ = IQ; RSA.ImportParameters(RSAparams); return RSA; } catch (Exception ex) { throw ex; // return null; } finally { binr.Close(); } } private static int GetIntegerSize(BinaryReader binr) { byte bt = 0; byte lowbyte = 0x00; byte highbyte = 0x00; int count = 0; bt = binr.ReadByte(); if (bt != 0x02) //expect integer return 0; bt = binr.ReadByte(); if (bt == 0x81) count = binr.ReadByte(); // data size in next byte else if (bt == 0x82) { highbyte = binr.ReadByte(); // data size in next 2 bytes lowbyte = binr.ReadByte(); byte[] modint = { lowbyte, highbyte, 0x00, 0x00 }; count = BitConverter.ToInt32(modint, 0); } else { count = bt; // we already have the data size } while (binr.ReadByte() == 0x00) { //remove high order zeros in data count -= 1; } binr.BaseStream.Seek(-1, SeekOrigin.Current); //last ReadByte wasn't a removed zero, so back up a byte return count; } /// <summary> /// PKCS8 文本转RSACryptoServiceProvider 对象 /// </summary> /// <param name="privateKeyPemPkcs8"></param> /// <returns></returns> public static RSACryptoServiceProvider LoadPrivateKeyPKCS8(string privateKeyPemPkcs8) { try { //PKCS8是“BEGIN PRIVATE KEY” privateKeyPemPkcs8 = privateKeyPemPkcs8.Replace("-----BEGIN RSA PRIVATE KEY-----", "").Replace("-----END RSA PRIVATE KEY-----", "").Replace(" ", "").Replace(" ", "").Trim(); privateKeyPemPkcs8 = privateKeyPemPkcs8.Replace("-----BEGIN PRIVATE KEY-----", "").Replace("-----END PRIVATE KEY-----", "").Replace(" ", "").Replace(" ", "").Trim(); //pkcs8 文本先转为 .NET XML 私钥字符串 string privateKeyXml = RSAPrivateKeyJava2DotNet(privateKeyPemPkcs8); RSACryptoServiceProvider publicRsa = new RSACryptoServiceProvider(); publicRsa.FromXmlString(privateKeyXml); return publicRsa; } catch (Exception ex) { throw ex; } } /// <summary> /// PKCS8 私钥文本 转 .NET XML 私钥文本 /// </summary> /// <param name="privateKeyPemPkcs8"></param> /// <returns></returns> public static string RSAPrivateKeyJava2DotNet(string privateKeyPemPkcs8) { RsaPrivateCrtKeyParameters privateKeyParam = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(Convert.FromBase64String(privateKeyPemPkcs8)); return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent><P>{2}</P><Q>{3}</Q><DP>{4}</DP><DQ>{5}</DQ><InverseQ>{6}</InverseQ><D>{7}</D></RSAKeyValue>", Convert.ToBase64String(privateKeyParam.Modulus.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.PublicExponent.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.P.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.Q.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.DP.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.DQ.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.QInv.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.Exponent.ToByteArrayUnsigned())); } #endregion /// <summary> /// 加载公钥证书 /// </summary> /// <param name="publicKeyCert">公钥证书文本内容</param> /// <returns></returns> public static RSACryptoServiceProvider LoadPublicCert(string publicKeyCert) { publicKeyCert = publicKeyCert.Replace("-----BEGIN CERTIFICATE-----", "").Replace("-----END CERTIFICATE-----", "").Replace(" ", "").Replace(" ", "").Trim(); byte[] bytesCerContent = Convert.FromBase64String(publicKeyCert); X509Certificate2 x509 = new X509Certificate2(bytesCerContent); RSACryptoServiceProvider rsaPub = (RSACryptoServiceProvider)x509.PublicKey.Key; return rsaPub; } /// <summary> /// pem 公钥文本 转 .NET RSACryptoServiceProvider。 /// </summary> /// <param name="publicKeyPem"></param> /// <returns></returns> public static RSACryptoServiceProvider LoadPublicKey(string publicKeyPem) { publicKeyPem = publicKeyPem.Replace("-----BEGIN PUBLIC KEY-----", "").Replace("-----END PUBLIC KEY-----", "").Replace(" ", "").Replace(" ", "").Trim(); //pem 公钥文本 转 .NET XML 公钥文本。 string publicKeyXml = RSAPublicKeyJava2DotNet(publicKeyPem); RSACryptoServiceProvider publicRsa = new RSACryptoServiceProvider(); publicRsa.FromXmlString(publicKeyXml); return publicRsa; } /// <summary> /// pem 公钥文本 转 .NET XML 公钥文本。 /// </summary> /// <param name="publicKey"></param> /// <returns></returns> private static string RSAPublicKeyJava2DotNet(string publicKey) { RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKey)); return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>", Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()), Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned())); } } }
-源码：https://gitee.com/runliuv/mypub/tree/master/donetproj